关键词: 初霜日, 终霜日, 无霜期, 变化特征, 鲁中地区

Abstract: In order to better grasp the impact of frost-free period on agricultural production in Luzhong area and improve the prediction of frost, making full use of national meteorological stations in Luzhong area to use linear trend estimation method, Mann-Kendall mutation analysis, T Sliding, ArcGIS spatial interpolation and other methods analyze the temporal and spatial variation characteristics of frost, the first day and the frost-free period and their relationship with climatic factors and geographical factors in Luzhong area. The results showed that the first frost day was significantly delayed, the final frost day was significantly advanced and the frost-free period was significantly extended in the Luzhong area. The years of mutation were 2003 and 1996 and 2003, respectively. The initial frost day and final frost day and frost-free period were closely related to temperature. The distribution of initial frost day and final frost day and frost-free period was uneven. The first frost days appeared earlier in the central mountainous areas, and gradually delayed from the east and west to the sides. The final frost day first appeared in the northwest. Later was the central and Changyi-Weifang-Anqiu area and the latest was Laiwu, Linqu, Weifang area. The frost-free period was the longest in the northwest, and the shortest appeared in the central and southern mountains. The initial frost day and the final frost day were positively correlated with altitude and longitude and respectively reached a very significant level. The frost-free period was negatively correlated with altitude, and reached a significant level with the influence of altitude.

Key words: initial frost day, final frost day, frost-free period, variation characteristics, Luzhong area